Rus, not Russians. Scandinavians who migrated south, in the same way Angles, Saxons and Jutes migrated across the water to Britain, at more or less the same time. Why the Rus have this special status in these kinds of discussions I’m not sure. No-one outside of some odd far right groups, afaik, thinks of England and Germany sharing the same kind of mythical bond, or at least not to the same maudlin degree. Ethnicity doesn’t determine some kind of parallel development. The culture, eventual ethnic mix, language and other elements of what constitutes a nationality of the Rus who settled in the area later called Kyivan Run, and those who settled in Muscovy, are within the same bounds of difference as between Celts, Angles, Turkic peoples and so on. There’s nothing Russian about Ukraine any more than there’s anything German about England, it’s all just vague rhetoric based on very little. The Hungarian speaking minorities here in Romania are not Hungarian, they are Romanians who speak a dialect of Hungarian - their culture is not the same as Hungarian culture beyond a few superficialities, the rest is myth. There’s no difference between that and the divergence of Ukraine and Russia, they are two separate nationalities. The Russian Federation itself is not really a country, just a confederation of partners with varying degrees of willingness. But somehow this notion that Ukraine is Russia has spread.